Book of Shadows
by A.Diamond
Summary: Arthur stared down from his throne at Geoffrey. Merlin knew the only thing keeping him from gaping was his sense of dignity. The normally unflappable librarian was in a state: his face pale and sweaty, his eyes wide and bloodshot, and his hair a complete mess. His trembling hands shook through it again, tousling the white nest further, as Arthur continued to stare.


Arthur stared down from his throne at Geoffrey. Merlin knew the only thing keeping him from gaping was his sense of dignity. The normally unflappable librarian was in a state: his face pale and sweaty, his eyes wide and bloodshot, and his hair a complete mess. His trembling hands shook through it again, tousling the white nest further, as Arthur continued to stare.

Merlin was sure that the next words out of Arthur's mouth would be mocking, disbelieving, or both. Instead, he stood suddenly; decisively.

"I will look into it immediately," he told Geoffrey solemnly and swept out of the throne room before anyone could do more than scurry out of his way. Merlin rolled his eyes and went after him.

He caught up to Arthur at the top of the wide stairs and followed him in exasperated silence almost all the way to the library, waiting for Arthur to say something. Since he didn't, Merlin had to know, "What are you doing?"

"Oh, just going to slay a book that spawns shadow monsters when you open it."

And there it was; now that he was alone (because of course Merlin didn't count), Arthur let himself snicker at what he saw as the absurdity of Geoffrey's complaint. Even after all these years, Merlin reflected, Arthur never took magical threats seriously.

"You don't think he could be right? Weirder things have happened."

"Merlin," Arthur scoffed. "We're talking about a book that's been in Camelot's archives for decades. If it were magical or dangerous, it would have been destroyed long before now. It's harmless. We'll go in there, everything will be fine, and we can tell Geoffrey we burned it or something so he can get some rest before he embarasses himself further."

Arguing with Arthur was worse than pointless—it just made him more resolved to be stupid—so Merlin kept his mouth shut and waited to see what disaster they were walking into this time.

As soon as Arthur opened the heavy library door, Merlin readied himself to protect the king from magical attack while trying not to give himself away. Nothing happened.

It did seem gloomier than usual, though. Shadows clung to the corners, darker and denser than they ought to have been, and the air itself felt heavy. The book in question loomed as menacingly as a closed book could loom on a central table, its cover burnt with runes that Merlin recognized as cautions against touching or opening it. The underside of the table was completely dark, despite the light that should have reached it from nearby lamps.

Arthur, naturally, noticed none of this.

"There, just as I said. Nothing to be worried about." He reached out and flipped open the book without giving Merlin time to stop him. "Just an old book about..." He rifled a few more pages, frowning and completely unaware of the dark shape forming behind him. "Half these words are gibberish."

The thing that coalesced at Arthur's back fit Geoffrey's description perfectly, and 'shadow monster' was as apt an epithet as any: It didn't move so much as shift through the air, a black warp half again as tall as Arthur with shadowy tendrils for limbs and no discernable head. It crept towards the oblivious king, flickering like an evil black candle as he continued to try and make sense of what he read.

Merlin had no frame of reference for this sort of creature, so he took a guess and sent a tiny fireball at with a whispered, " _Forbærne_."

It vanished into the monster's shadowy depths without appearing to harm it at all, snuffed out after only a moment. The monster did take notice, though, and turned its attention on Merlin. Without giving him a chance to worry, a ring of shadow—less black than the monster itself, but still noticeably dark—wrapped itself around Merlin's chest and constricted.

Despite being able to see through the band of dimness trying to crack his ribs, Merlin couldn't grasp it or pull free. It squeezed tighter and tighter, threatening to squish the breath out of him in a pained cry that he only held back with the knowledge that Arthur turning around would ruin everything.

He needn't have concerned himself about that. "Maybe I should have Gaius take a look at this," Arthur mused to himself as spots danced in Merlin's vision. "Not for any magical properties, but maybe he'll understand it. I think it might be written in two different languages, and I don't know the other."

Unable to form a proper spell and at the edge of losing consciousness, Merlin was quickly running out of options. After a few more crucial seconds of not being able to come up with anything, he decided that the worst that could come of Arthur discovering he was a warlock was Arthur trying to execute him, and he at least had a chance of getting out of that. He could even disguise himself and hang around to save Arthur if he got exiled. If he let this thing kill him now, Arthur would be next, and that would be the end of that.

Merlin closed his eyes, Arthur's puzzled mutterings a soothing background noise as he let his magic run wild, erupting through his veins without constraint to do whatever it needed in order to save him. It was usually pretty good at that.

Sure enough, he felt it start to flow outward from his chest and the monster's hold on him loosened, then vanished completely. Still trying to catch his breath, he opened his eyes in time to see the last traces of the shadow monster fade away as light brightened the space where it had been.

"Well, it hardly matters. You see, Merlin?" Arthur said as he snapped the book shut and picked it up. "I told you it was completely harmless."

"Yes, sire." Merlin struggled to speak evenly instead of gasping, his hands trembling as he clutched as his aching ribs. "Harmless."


End file.
